Abstract: At least a partial seal between a housing of a hearing instrument and an ear canal is provided. First signals are received from an internal microphone disposed in the ear canal. Second signals are received from an external microphone disposed outside of the ear canal. A condition of the at least a partial seal is determined, and when the condition of the at least a partial seal indicates a leak, one or more of the level and the spectrum of the first signals is adjusted to compensate for the leak and producing first adjusted signal. A first amount of the first adjusted signals is blended with a second amount of the second signals to produce a blended signal, the first amount and the second amount selected based upon a level of noise.